1. Technical Field
The present invention relates to a non-woven fabric with a favorable soft hand and a superior mechanical strength and elongation, and to polyester fibers for the production of the former.
2. Background Art
The technique for the production of a wet type non-woven fabric by utilizing chopped fine polyester fibers is known in the art, as disclosed in Japanese Unexamined Patent Publication (Kokai) Nos. 57-11209, 57-16916 or 57-139554. When such fine polyester fibers are produced by a conventional process, problems arise of a lower productivity due to a low discharge rate of a fiber per spinneret and of a high rate fiber breakage during the spinning operation due to a finer thickness of the fibers, which increase production costs. Moreover, the resultant non-woven fabric cannot provide a satisfactory quality due to many defects generated therein during a paper making process, although having a desirable soft hand.
Methods of obtaining fine polyester fibers through a flow drawing process have been disclosed in Japanese Examined Patent Publication (Kokoku) Nos. 28-617, 36-20772, 43-16670, 55-6734, and 55-14171, but no proposals have been made for the utilization of fibers obtained from these processes, as a material for a wet type non-woven fabric; because the fine polyester fibers obtained from a flow drawing process are sticky and have a poor openability, and thus many defects tend to occur during the paper making process.
Further, it is known to produce a wet type non-woven fabric with undrawn polyester fibers, but the undrawn polyester fibers obtained from a conventional spinning system have a thickness of at least 1 denier, and if thinner fibers are desired, a special quenching device must be used in the spinning system, as proposed in Japanese Examined Patent Publication (Kokoku) No. 63-17921. Nevertheless, the spinning conditions remain unsatisfactory even though such a device is utilized.